Open core

This article is about a software business model. For open source hardware cores, see OpenCores.

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The concept of open core software has proven to be controversial, as many developers do not consider the business model to be true open source software. Despite this, open core models are used by a large number of open source software companies.[4]

Talend uses an Open Code license for its data management, data integration and cloud products.

It has been suggested by Bradley M. Kuhn that Canonical Ltd., maintainers of Ubuntu are preparing to go open core, but have not done so,[5] according to the Canonical's contributor agreement and their Project Harmony which aimed "to assist organisations which use contribution agreements by providing standardised variable templates with clear and concise explanations...."[6]

Some open core models use copyright assignment, but it should be pointed out that some open source projects require assignment of copyright for the sole purpose of defending that copyright, with the promise of retaining (only) open source licensing. For example, by prosecuting modification and binary release of GPLed software without release of the modified source code.

Organisations which see open core as a danger include clauses in their assignment to prohibit open core licensing. One example is Free Software Foundation Europe's (FSFE) Fiduciary Licence Agreement (used by KDE[7]). In this agreement, developers assign copyright to FSFE, but FSFE promises to use a free software licence when distributing the software:

FSFE shall only exercise the granted rights and licences in accordance with the principles of Free Software as defined by the Free Software Foundations. FSFE guarantees to use the rights and licences transferred in strict accordance with the regulations imposed by Free Software licences, including, but not limited to, the GNU General Public Licence (GPL) or the GNU Lesser General Public Licence (LGPL) respectively. In the event FSFE violates the principles of Free Software, all granted rights and licences shall automatically return to the Beneficiary and the licences granted hereunder shall be terminated and expire.[8]

Other projects that use copyright assignments but which promise not to distribute the software as open core include the GNU Project.[9]